1. Field of the Invention
Embodiments of the present invention generally relate to electronic device manufacturing and more particularly to methods and apparatus for improved sealing of an opening in a plasma processing chamber.
2. Description of the Related Art
In the fabrication of flat panel displays, television or computer monitors, solar cell arrays, and the like, various dielectric, semiconductive, and conductive layers are sequentially deposited on surfaces of substrates. These substrates may be made of glass, polymers, metal, or other suitable substrate materials capable of having electronic devices formed thereon. To increase fabrication efficiency and/or lower production costs, the size of the substrates to be processed continues to increase. As a result, the size of processing chambers for forming the layers on the surface of the substrates continues to increase as well.
A substrate processing chamber typically communicates with a substrate transfer chamber through a sealable opening that is both wide and relatively short to accommodate insertion and removal of horizontally-oriented substrates. A chamber isolation valve, also known as a slit valve, may be positioned adjacent the processing chamber to seal such an opening.
For example, an isolation valve may be attached to the processing chamber such that a sealing plate, also known as a door, of the isolation valve may be extended to seal the opening, and retracted to permit passage of substrates through the opening.
Unfortunately, as the size of the substrates, and corresponding size of the needed opening in the process chamber, continues to grow, so do problems associated with current sealing systems associated with plasma uniformity, gas flow, particle contamination, and temperature uniformity. Accordingly, a need exists for improved methods and apparatus for sealing the opening of a process chamber.